涼しいブラウン・ダワーヌ Gliese 229 B は,密接なバイナリである
Jerry W Xuan1, A Mérand2, W Thompson3
1Department of Astronomy, California Institute of Technology, Pasadena, CA, USA. wxuan@caltech.edu.
Nature
|October 16, 2024
まとめ
巨大な惑星に似た ブラウン・ダワーフが 恒星の形成理論に 異議を唱えています 観測により,Gliese 229Bは実際にはGliese 229BaBbという二重星系であり,二重の茶色矮星形成に関する不一致を解決し,新しい疑問を提起しています.
科学分野:
- 天文学と天体物理学
- 外惑星科学
- 恒星と亜恒星物体の形成
背景:
- ブラウン・ダワーフの伴星は 巨大系外惑星との類似性により 惑星の形成と進化の洞察を 提供しています
- いくつかの茶色矮星は,輝度と宿主星の年齢によって予測されるよりも大きいので,不完全な理論または複数の構成要素を示唆しています.
研究 の 目的:
- 理論的な予測と観測されたブラウン・ダワーンの同伴星,特にグリーゼ229Bの質量の差異を調査する.
- 明らかに単一の物体である Gliese 229B を構成要素に分解する.
主な方法:
- GRAVITYインターフェロメーターを用いたGliese 229Bの観測.
- 非常に大きな望遠鏡のCRIRES+スペクトログラフを用いた独立した観測.
主要な成果:
- 両方の観測群は,Gliese 229BをGliese 229BaとGliese 229Bbの2つの構成要素に分解した.
- 構成要素の質量はそれぞれ38.1 ± 1.0と34.4 ± 1.5の木星質量 (MJup) である.
- 周回周期は12.1日,半大軸は0.042AUである.
結論:
- グリーゼ229BaBbという二重の茶色矮星系の発見は,理論的モデルと観測データとの矛盾を解決した.
- この発見は,恒星の周りのコンパクトな二重ブラウン・ダワーシステムの形成メカニズムと流行に関する新しい疑問を投げかけます.
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